1. Field of the Invention
The present invention relates to threaded fasteners such as screws, bolts and nuts, and more particularly, to anti-cross threading fasteners.
2. Description of the Related Technology
Threaded fastener technology is basic to the construction or fabrication of most articles of manufacture such as machines, automobiles, trains, plains, engines, and the like. Threaded fasteners may be bolts, screws, studs, rods, or other substantially round members having uniform, non-uniform or tapered external helical threads that are screwably engaged into mating threaded fasteners such as nuts, bolts or holes having substantially matching internal helical threads. For proper engagement of the externally and internally threaded fasteners, the longitudinal axis of the externally threaded member must be substantially collinear with the longitudinal axis of the mating internally threaded member. When the externally threaded member is not substantially collinear with the internally threaded member, cross-threading occurs.
Cross-threading generally occurs when there is a misalignment between the externally threaded member, typically a screw or bolt, and the internally threaded member, typically a nut or other threaded hole. Specifically, cross-threading is the result of the threads of the two members attempting to engage at least one half pitch out of alignment. When this situation happens, the two members are not collinear with each other and wedging of the threads will occur as the threaded helixes are rotated against each other. If rotation continues, then threads on one or both members will be structurally damaged.
What is needed is a fastener that prevents cross-threading when an externally threaded member engages an internally threaded member.